More than a dozen residents and activists in the attack areas told Human Rights Watch they believed that as ISIS began freeing Sunni prisoners elsewhere as it advanced south, Iraqi security forces and militia killed the prisoners to prevent them from joining the rebellion, as well as to avenge ISIS killings of captive government troops.
The murder of detainees during armed conflict is a war crime and, if carried out on a large scale or in a systematic manner, as a state policy, it would be a crime against humanity.
Iraq's government has in the past denied allegations that it summarily executed prisoners. The Defense and Interior Ministries did not reply to requests for comment from Human Rights Watch on the five cases it documented.
Human Rights Watch interviewed more than 35 people in person or by telephone about the five attacks. They included witnesses and relatives of those killed, security and other government officials, and local activists. Many had fled their homes and spoke on condition of anonymity, fearing reprisals by government forces. Human Rights Watch also reviewed video footage, still photos and media reports of the killings.
Reuters news agency, quoting police sources, reported that in a sixth attack, on June 23 in central Babil province, police executed 69 prisoners in their cells in the city of Hilla before transferring their bodies to Baghdad later that day.
The government has been fighting Sunni armed groups in Anbar since January 1. ISIS and other Sunni armed groups captured Mosul, Iraq’s second-largest city and capital of Nineveh province, on June 10, then moved through other areas across Iraq.
The majority of prisoners killed in the five attacks had been rounded up under article 4 of Iraq’s anti-terrorism law, but had not been charged with any crime. Some had been imprisoned for months, while others were detained shortly after ISIS began its takeover of Mosul on June 9.
In the first attack, on the night of June 9, prison guards removed 15 Sunni prisoners from their cells at the Counterterrorism and Organized Crime prison, in the heart of Mosul, a former prisoner told CNN. The prisoner later told Human Rights Watch that the men were Sunnis from the minority Turkmen community.